(1 → 5)-linked β- d-galactofuranosides are immunodominant in extracellular polysaccharides of Penicillium and Aspergillus species

Abstract

Aspergillus and Penicillium species produce extracellular polysaccharides which are immunologically active. Methyl β- d-galactofuranoside interferes with the reaction between the polysaccharide antigens and the antibodies raised in rabbits. Of the different interlinked dimers of β- d-galactofuranosides (1 → 2; 1 → 3; 1 → 5; 1 → 6) the (1 → 5) interlinked β- d-galactofuranoside gave the highest inhibition. An increasing inhibitory effect of di-, tri-, tetra-, penta-, hexa-, and heptamers of (1 → 5) interlinked β- d-galactofuranosides was observed. It was noticed that the penta-, hexa- and heptamer of (1 → 5) interlinked β- d-galactofuranosides were able to link antibodies raised against the extracellular polysaccharides produced by Penicillium species. The tetramer molecule was able to neutralize the binding of antibodies, which are naturally present in human sera, to the polysaccharides produced by Penicillium and Aspergillus species.